According to the prior art, blood plasma suspensions are presently separated using vertical solid-bowl centrifuges or chamber separators or by filtration methods.
Filtration of blood plasma is carried out via filter presses or vertically arranged rotary pressure filters. The throughput capacity which can be achieved thereby is relatively high. However, in most cases a filter aid has to be added to the suspension, namely a porous, finely particulate material which increases the permeability of the filter cake forming in the filter. This has a significant influence on the procedure for further processing to give the end product.
When using filters for the separation of blood plasma particles, the main problem, however, lies in the complicated manual handling which is needed for emptying the filter and cleaning it, and in the associated risk of contamination to which operating staff and product are equally exposed. A further disadvantage of this method is that the filters used according to the prior art cannot be cooled, and the procedure therefore has to be carried out at relatively low ambient temperatures. This entails high costs associated with air conditioning.
Alternatively, the separation of blood plasma particles in chamber separators is known. Chamber separators are characterized by a drum which is mounted on a vertical spindle, without automatic discharge of the separated solid, and which is filled from above via a vertical line and, in order to improve the clarification effect, is in most cases divided into a plurality of chambers. These centrifuges can be cooled via the housing. The throughput capacity is relatively high. However, the use of chamber separators for the separation of blood plasma particles also has the disadvantage that the drum and other component parts coming into contact with the product have to be removed and cleaned by hand, which exposes operating staff and product to a high risk of contamination. Moreover, with this type of machine, no design is known in which the drive unit is spatially separate from the processing unit, which separation is desirable in view of the increasing hygiene demands.
A more automated method for the separation of blood plasma particles is possible using a vertical solid-bowl centrifuge with scraper device. It is known that this type of centrifuge permits automatic discharge of solid and automated cleaning of the drum and of the parts coming into contact with the product. Centrifuges of this type achieve their separating efficiency principally by means of very high drum speeds. However, the separating efficiency is limited because the surface area on which the blood plasma particles are deposited is restricted for construction-related reasons. The high peripheral speeds which arise in centrifuges of this type require a relatively high level of cooling in order for the drum and the product situated in the drum to be kept within the desired temperature range. For this reason, the space surrounding the drum is often placed under vacuum in order to reduce the air friction heat. The solid is discharged via a scraper system which automatically scrapes the deposited solid out of the drum. The solid then falls into a container arranged underneath the drum. Because of their relatively complicated structure, the use of vertical solid-bowl centrifuges with scraper system for separation of blood plasma particles is relatively expensive, and the assembly operations are often laborious.
Against the background of the known methods for the separation of blood plasma particles, the invention aims to create the essential advantages of said manual methods, i.e. the use of a chamber separator or filtration, together with the essential advantages of the automated method, i.e. similar to the use of a vertical solid-bowl centrifuge. Therefore, the object of the invention is to make available an inexpensive and straightforward but also fully automated centrifuging method with a high throughput capacity of the equipment for the separation of blood plasma particles from a suspension, which method, however, permits cooling of the drum without the need for a vacuum in the area of rotation of the drum and ensures separation of the processing space and drive space in order in particular to satisfy the strict hygiene requirements. Assembly operations on machines used for this method are to be able to be carried out comparatively easily.
According to the invention, this object is achieved by using an automated centrifuge with baffle plates for increasing the active surface area for separation of blood plasma particles from a blood plasma suspension.